The Magdalen in a Landscape, Adriaen Ysenbrandt
In the National Gallery, London. Also on Google Art Project, downloadable file on Wikimedia Commons.
Painted in the early 16th century, this delicately rendered devotional piece features a truly strange landscape, including a scene within a scene in which Mary is shown reading in a rather bizarre little cave. There are beautiful touches in the detailed rendering of the book, jar and and flowers.
In contrast to the other background elements, the large tree is naturalistic in a way similar to the styles of later centuries.